The overall goals of this proposal are to serve as one of the clinical centers in the Parkinson's Disease (PD) Clinical Neuroprotection Trial and to participate in the large, collaborative, randomized, double-blind trial testing neuroprotective agents in patients with early PD. Our program represents a multidisciplinary, interactive and collaborative group of investigators and clinicians who have long been committed to the studies and care of patients with Parkinson's disease and other related neurodegenerative diseases. Our aim will be to recruit and follow PD patients, including women and minority patients, early in their clinical course per established protocol and rates established by the PD Neuroprotection Clinical Trial.PD is the second most common neurodegenerative disorder, and it affects nearly I million Americans. Although available medical therapies are effective for the treatment of PD early in its course, there are no proven agents that prevent or slow the progression of the neurodegeneration of PD. Tremendous insight into the mechanisms of neurodegeneration of PD has created an opportunity to begin to rationally study potential neuroprotective agents in the treatment of this disorder. As part of the Parkinson's disease research agenda for the NIH published in April 2000, there was a call for the initiation of randomized, controlled clinical trials to test potential neuroprotectants in PD. We propose to participate as one of the clinical centers in this large collaborative trial testing neuroprotective agents in patients with early PD. To address the goals of the trial, we will (1) recruit and follow PD patients, including women and minority patients early in their clinical course per established protocol and rates established by the PD neuroprotection clinical trial; (2) operate a clinical center to a) enroll patients, b) monitor and examine patients per protocols established by the coordination center, c) record, manage, maintain and process clinical trial data, and provide the data to the coordination and statistical centers, and d) ensure safety of subjects and confidentiality of data; (3) adhere to common protocols and cooperate with other centers and the NINDS in the conduct of both pilot studies and the main efficacy studies; and (4) maintain an administrative structure that allows for close collaboration with the selected coordination and statistical centers, other clinical centers, NINDS scientific program personnel, the NIH oversight committee, referring physicians, and lay organizations and support groups.